Roller-hearth furnace



June 17, 1930. F. T. COPE ROLLER HEARTH FURNACE Filed Oct. 11, 1928 4 SheetsShe e t OOOOOOQOOO0 000000000000WMVOOOOOOOOOOOO o o o o o o o o o o o o o m o o o OOOOOOOOOOOOOOOOOOOO Zlmzntoz fi'a/zk 77, Cape dbtomw June 17, 1930. F. T. COPE ROLLER HEARTH FURNACE 4 Sheets-Sheet 2 Filed Oct 11. 1928 N Ma Fran/t June 17, 1930. A F. T. COPE 1,764,007

' ROLLER HEARTH FURNACE Filed Oct. 11. 1928 4 Shgets-Sheet 3" Q M63 W 0 :Z M n I R MM v I R M a U I F. "r. COPE ROLLER HEARTH FURNACE June 17, 1930.

Filed ochu, 1928 4 Sheets-Sheet 4 mm Fran/i 7T 60/06 Patented June "17, 1930 UNITED STATES PATENT OFFICE FRANK '1. COPE, OI SALEM, OHIO, ASSIGNOR 1'0 THE ELECTRIC FURN ACE COMPANY,

OF SALEMI, OHIO, A. CORPORATION OF OHIO nounannmvrn summon Application filed Qctdber 11, 1928. Serial No. 811,888.

The invention relates to furnaces of the continuous or intermittent type and the ob- 4 ject of the improvement is to provide a furnace having two superposed heating cham- 5 bers separated from each other and arranged to be independently heated whereby floor space may be conserved.

Although the invention contemplates a furnace in which both chambers may operate at the same temperature, for carrying on similar heat treatment, an advantage of this construction is that the chambers ma be operated at,

different temperatures where y material may be hardened in one chamber quenched and then passed through. the other chamber at a lower temperature for drawing. A further object is to provide a combined roof for the lower heating chamber and hearth or floor for the upper chamber, preventing heat loss by radiation. I

Another object of the improvement is to provide a roller hearth in each chamber, the rolls being operated by a ratchet drive so constructed as to permit close roll spacing and also to permit withdrawal of the rolls for repairing or replacements.

A still further object is to provide a switch adjacent to the dischargeend of each heating chamber and arranged to be automatically 3o operated by the material approaching the dis H arge end of the furnace to light a warning light, giving notice that the exit door must be opened to let the material pass out of the chamber, the switch having a delayed action trated in the accompany drawings, in which timer which stops the movement of the hearth rolls in the event the exit door is not im Figure 1 is a side elevation of the improved furnace Fig. 2, a transverse sectional view the furnace;

Fig. 3, a fragmentary elevation of a portion of one end of the furnace showing a part of one heating chamber in section;

Fig. 4, an enlarged detail sectional view showlng one of the hearth rolls andthe pawl and ratchet'operating mechanism therefor;

Fig. 5, a fragmentary side elevation upon an enlarged scale of a portion of the pawl and ratchet operatingmeans for the hearth rolls;

through i Fig. 6, a wiring diagram of the circuit to v the switch and delayed action timer which operates the warning signals and controls the motor which operates the roll driving mechanism; and

Fig. 7, a front elevation of one ofthe seal plates for preventing leakage of air around the hearth rolls.

Similar numerals refer to similar parts throughout the drawings.

The furnace may be constructed of a suitable metal shell 10 provided with refractory lining 11 and supported upon beams as at 12, a superstructure 13 being provided above the furnace for carrying the operating mechanism. v

The upper and lower heating chambers 14 and 15, respectively, may extend entirely through the furnace, being separated by the partition wall 16 which forms a combined roof for the lower chamber and floor for the upper chamber, thus preventing heat loss by radiation at this point.

For the purpose of continuously or intermittently passing the material to be treated through the furnace, each heating chamber may be provided with a roller hearth comprising the spaced rolls 17. Independent means may be provided for separately heating each of the heating chambers, preferably electric resistors such as shown at 18, which may be located above and below the roller hearth in each chamber.

Each of the rolls 17 is preferably in the form of a straight shaft j ournaled in bearings 19 carried by the channel beams 20 which are supported upon each side of the furnace.

of the furnace as by the coil spring 23 inter-' posed between the adjacent bearing 19 and theseal plate.

- A grease pocket 24 isformed 1n the upper portion of each seal plate and communicates by a small passage 25 with the central opei'n ing 22 whereby grease from the pocketwill form a film around the shaft, sealing the opening through the side wall ofthe furnace and preventing the passage of air into or out of the furnace at this point. A stud 26 may be fixed upon theside wall of thefurnace for engagement with the aperture 27 in the lower portion ofthe seal plate to hold the same in upright position.

, A ratchet wheel 28 is fixed upon one end of each roll shaft in any suitable and well known manner and a collar 29 isfixed upon the other end portion thereof, a coil spring 30, preferably heavier than the springs 23, being inter-.

posed between-said collar and the adjacent bearing 19, thereby holding the ratchet Wheel in position against the other bearing 19.

For the purpose of operating the rolls 1? in unison, a reciprocating ban-31 is located upon the outside of the furnace adjacent to theratchet wheels 28 of each roller hearth. As shown in the drawings, this bar is preferably of inverted channel form and located above the ratchet wheels, being mounted for reciprocation as by the yokes 32 and rollers .33.

A plurality of pjawls 34, corresponding in number and position to the ratchet wheels 28,

is carried by each reciprocating bar 31, each pawl being pivotally connected to the bar as by a pin 35., v

Each reciprocating bar is'adapted to be reciprocated by means of a bell crank 36, the lower arm 37 of which is bifurcated asat 38 to receive a block 39 pivoted as at 40 upon thebar 31.

The upper arm 41 of each bell crank lever is connected by a link 42 with an eccentric band 43 mounted upon an eccentric 44fixed upon ashaft.45. These shafts are driven at a reduced speed through the reducing gears 46 which are operatively connected as bychains 47 with the shaft of amotor 48.

It will be seen that with each reciprocatio of the bar 31 the pawls will be moved from the dotted line position, shown in Fig. 5, to the full line position in said figure, rotating each'roll the distance of one ratchet tooth and then returnin to the dotted line position.

All of the rolls in each hearth will thus be slowly rotated in unison, moving the material across the hearth from the inlet end of the furnace toward the discharge end thereof.

Doors, 49 may be provided for normally I closing-the discharge ends of the heating chambers and as material nears the discharge insane! end of each heating chamber it is necessary to raise the door to permit the material to be discharged.

These doors ma bemanu'ally operated or ma be raised and owered by any suitable and we known means coon for such purposes, the particular means for operating the doors forming no part of the invention.

In the event the discharge door is not opened whenmaterial approaches the same, it will be seen that the material will pile up against the door, causing damage to the door or material or probably to both. For, this reason the invention contemplates the provision of an automatic sial for notifying the operator when material approaches the discharge door.

This device may include a trip arm 50 pivoted as at 51 and located in the path of the material adjacent to the discharge door 49 of each heating chamber. A rocker arm 52 is fixed to the trip plate 50 and connected by a link 53 with a lever 54 pivoted as at 55 and having a counterweight 56 at its opposite end i to normally hold the parts in the position shown in Fig. 3.

Three switch fixed upon an insulation block 58 carried by the lever 54 and are arranged to simultaneously contact-with the three contact points 59 connected to a wire 60 arranged to be connected through any suitable switch and fuse device at 61 with the line wire 62. lt'should be understood that two of these switch devices are provided, one for controlling each heating chamber. As indicated on the drawings, the switch device for controlling the upper heating chamber is designated at A and that for controlling the lower chamber at B. p

The switch blade 57 of the switch device A is connected by a wire 63 with signals which may be in the form of lights 64 located at opposite ends of the upper chamber, a wire 65rleading from said lights to the point 66 where it is connected as by the switch and fuse device 61 with the line wire 67. A wire '68 connects the switch blade 57 of the switch device B with similar signal lights 69 located at opposite ends of the lower chamber, said lamps being also connected to the return wire A wire 70 connects the point 66' with a switch contact '71 which is also connected with a-resistor 7 2, which is in turn connected by a wire 73 with the coil 74 ofthe relay switch comprising the blades 75 and 76. This relay coil isconnected by a return wire 77 blades 57, 57 and 57" are with the oint 78 which is connected through the switc and fuse device 76 with the line wire 62. 1

' A wire 79 connects to the wire 73, between the resistor and the relay coil 74 and leads to a'contact finger or blade 80. A similar blade 81 cooperates therewith to make interwire 85 with both of the switch devices A and B.

mittent contact with one of theth'ree spaced plates 83 upon the rotary cylinder '84 formed of insulation material.

The blade or finger 81 is connected by a of the switch blades 57' indicated at 94. A switch blade 95 is con-' nected by the wire 96 with the motor 48 and adapted to contact with the contact point 94 upon the wire 89.

A similar switch blade 97 is adapted to contact with the point 94 upon the wire, 90

48. A third switch blade 100 of this switch is connected, througha noninductive resist-. ance 101, to a wire 102 also leading to the 9 motor. v

The coil 103, which controls these three switch blades, is connected by a wire 104 with the switch blade 75 and upon its other side by a wire '106 to the switch blade 76, a manually operated emergency switch 107 being located in said wire between the coil and switch blade 76.

The rotary controller 84 is provided wlth a spindle 108 of conductor material connected toa disk 109 also of conductor material and located at one end of the cylinder. This disk is connected by bus bars 110 with a broken ring 111 located around the cylinder and adapted to be engaged by the finger or blade 112 connected to the wire 88. A similar finger or blade 113 is adapted to contact with the spindle 108 and is connected by a wire 114 with .the point 78.

In the operation of the furnace'the switches 61 and 92 are closed. Current passes from the line wire 67 through the wire 70, resistor 72, I

coil 74 of the relay switch and wire 77 back to the line wire 62, energizing the coil 74 and holding the switch blades 75 and 76 in contact with the switch points 71 and 115 respectively.

The circuit is thus closed through the wires 104 and 106 through the coil 103 of the relay switch in the motor starter, closing the switch blades 95, 97 and 100 upon the switch points 94. Current is thus furnished to the motor from the line wires through the wires 89, 90 and 91 and through the motor starting switch and wires 96, 99 and 102.

The motor through the drive mechanism above described will continuously reciprocate the bars 31 and through the pawls thereon and ratchets upon the rolls, the hearth rolls will all be rotated in unison. As a piece of material nears the discharge end of the furnace 'ltwill depress the trip plate 50 and with will close the switch blades 57, 57" and 57 of that particular switch upon the corresponding switch points 59.

through the levers and links associated'there- Assuming that a piece of material in the- '4 upper chamber depresses the trip plate therein, the switch blades of the switch device A will be closed'and the circuit will then be closed from the point 61 through the wire 60, switch blade 57 and wire 63 to thesignal lamps 64 and thence through the wire 65 to the point 66. The lighting of these signal a piece of material is nearing the discharge door and the door must'be opened to permit material to. be discharged from the heating chamber. and is connected, through a nonmductlve resistance 98, to a wire 99 leading to the motor At the same time the circuit is closed from the point 61 through the wire 60, switch blade 57, wire 88, clock motor 87 wire 86, switch blade and wire 7 Oto the point 66, starting the clock motor. The cylinder 84, being operatively connectedto the clock motor, starts to rotate at the same time.

If the door is not opened to discharge the material within a predetermined time, which may be twenty seconds from the time the signal lights are lit, the blades and 81 willcontact with one of the plates 83, closing the circuit from the wire 79 to the wire and shorting out the relay coil 74, causing the switch blades 75 and 76 to open.

This breaks the circuit to the coil 103, opening the switch blades 95, 97 and 100 in the motor starter and the motor immediately stops. The clock motor will then stop.

As soon as the door is opened and thematcrial removed from the discharge end of the heating chamber, the switch device A will be opened by means of the counterweight and the relay 74 will make contact and the coil 103 will be energized, closing the switch in the motor starter andthc conveyer motor will again start to operate;

The timing device will start to operate and move to the starting position, with the finger 112 registering with the break in the conductor ring 111, at which pointfit will stop.

I claim: I

1. A furnace includinga heating chamber,

hearth rolls located through the heating chamber. bearings for the rolls spaced from the sides of the furnace, a seal plate located around each end portion of each roll, and

springs between the bearings and seal plates for holding the seal the furnace.

plates against the sides of 2. A furnace including a heating chambeigiiii hearth rolls located through the heating-. rolls spaced from" chamber, bearings for the the sides of the furnace, a seal plate located 80 lamps will give warning to the operator that said collar and the ad acent holding the ratchet wheel against the other of the heating chamber.

' crating the discharge end of the heating chamber and hearth rolls' located t other'end of each roll and a spring operated by nace, a ratc et wheel upon one end of each roll, a removable collar upon the other end of each roll .and a stronger spring between bearing for bearing.

3. A furnace including a heating chamber, rough the heating chamber. bearings for the rolls at opposite sides of the furnace, a ratchet wheel .upon one end of each roll, a removable collar upon the between said collar and the adjacent bearing for bolding the ratchet wheel against the other bearing.

4. means for passing material'throu'g the heating chamber, a signal outside of the furnace, and means located inside of the heating chamber extending through the passing means and the material passing through the heating chamber for operating the signal when material approaches the discharge end 5. A furnace ncludin a heating chamber, means'for passing materlal through the heating chamber, a signal outside of the furnace, and means controlled by the material for 0pthe signal when material approaches .within the heating 0 block pivoted on the bar, a bell crank engaging said block, and means for moving sa1d bell crank.

9. A furnace including a heating chamber, a hearth formed of a plurality of rolls located amber, a ratchet wheel upon each roll, a reciprocatory bar adjacent to the ratchet wheels, pawls upon the bar for engagement with the ratchetwheels, and

means for reciprocating the bar for rotating the rolls in umson to move material through the heating chamber including a block pivoted on the bar, a bell crank engaging said block, and means for moving said bell crank.

In testimony thatI claim the above, I have my name.

hereunto subscribed I FRANK T. COPE.

A furnace including a heatin chamber,

means for stopping. the passing means at a j I hearthrolls, means for rotating the rolls for.

passing material through the heating chamher, a signal outside of the furnace, and means controlled by the material for operating the signal when material approaches the discharge end of the heating chamber and means for stopping the rotation of the hearth rolls at a predetermined time after the operation of the signal.

7 A furnace including a heating chamber, hearth rolls, means for rotating the rolls for passing material through the heating chamber, a signal, mfians controlled by the material for operati g the signal when material approaches the discharge end of the heating chamber and for stopping the rotation of the hearth rolls a predetermined time after the operation of the signal, and means for automatically starting the rotation of the rolls when said material is removed.

8. A furnace including a heating chamber. a hearthformed of a lurality of rolls located within the heating chamber, a re'ciprocatory bar located adjacent to the rolls, means upon the bar for operative engagement'with the. rolls,. and means for reciprocating the bar to rotate the rolls 1n unisonv to move material.

through the heating chamber including. a 

